Re: Line wrapping during redisplay

[Chong Yidong]

> Actually, since I am a cleartext guy, I want my texts wrapped in their
> files.  Those are almost always TeX files, and TeX does not like 50000
> character lines, anyway.  Also, I have syntactical indentation in
> AUCTeX, and this sort of display-induced wrapping would not help
> much.
>
> So I am not really much of a customer of longlines.el, anyway.  Your
> display-based approach would probably have the advantage that the line
> numbers in the source still correspond with the line numbers on file,
> making error messages turn out correctly.

A relatively easy way to extend longlines.el is to write a function that
intelligently converts a buffer full of hard newlines into a longlines
buffer.  The simplest (but probably not the best) heuristic is to make
"\n\n" hard newlines, and single "\n" characters soft newlines.  Then you
can have a file full of newlines that plays well with latex, and other
programs that expect newlines.  When the file is loaded into Emacs, you
can use this function to turn into a longlines buffer, so you get the line
wrapping functionality.  Error message line numbers would correspond to
the line numbers in the buffer.  (With the display-based approach, even
though the line numbers turn out correctly, it may be hard to find the
error; for example, "line 3" may be a paragraph that takes up 50 screen
lines.)

One thing that longlines.el is unlikely ever to accomplish is support for
proportional fonts and images.  That is the big advantage of Kim's
approach (which makes the planned "longlines-2" obsolete, so it's a good
thing I haven't done much work on it ;-)  Another advantage of the
display-based approach is that it will never screw up font-lock
highlighting, as longlines.el often does.